In recent years, there has been a demand for making a more detailed temperature measurement in a certain space or region in various fields. For example, there have been a demand for finely measuring a particular region of the human body (for example, a temperature of the inner periphery of a tubular organ) during surgery or the like one the human body, and a demand for finely measuring a temperature in a certain space in a plastic greenhouse or the like. In such a case, measurements are made with a temperature sensor being placed on some sort of device such as a cable. As finer measurements are desired, a larger number of sensors need to be mounted inevitably.
When many sensors are installed using a cable as a device, the number of core wires for receiving signals from the sensors increases along with an increase in the number of the sensors. This leads to a larger finished diameter and poor flexibility. Moreover, there is a need to explicitly discriminate which core wire is connected to a sensor installed at which position. In this regard, an invention such that the identification is made on the basis of a combination of colors of core wire covering, and the like has been known as in the invention described in Japanese Utility Model Application Laid-Open No. Hei. 6-5040, for example.